<?php
        class SF_AutoCoupon_Model_Ruleitem
        {
            public function toOptionArray()
            {
                $result = array();
                $rule =  Mage::getModel('salesrule/rule')->getCollection();
                $filter = $rule->addFieldToSelect('rule_id')
                ->addFieldToSelect('name')
                ->getData();
               foreach ($filter as $k=>$v){
                   $result[$k]['value'] = $v['rule_id'];
                   $result[$k]['label'] = $v['name'];
               }
               return $result;
            }
        }